Today, we'll look at tunnels from an odd angle. The
University of Houston's College of Engineering
presents this series about the machines that make
our civilization run, and the people whose
ingenuity created them.
So much of our technology
seems to express basic human urges. We want to fly
through the air, to communicate with each other, to
travel about freely. And I remember, as a small
boy, wanting to tunnel -- to hollow my own house
out of a snowbank, to dig my own cave in the back
yard, to explore the huge sandstone caves along the
Mississippi.
And sure enough, we find that tunneling has drawn
one great engineer after another into startling
excesses of construction. The ancients were greater
tunnelers than most of us realize -- and I don't
mean just catacombs and crypts. In 525 BC the
Greeks cut a six-foot-square water-supply tunnel,
2/3 of a mile long, on the island of Samos. The
Romans connected two towns with the mile-long
30-foot-wide Posilipo road-tunnel in 36 BC.
But the great civil engineers of the 19th century
were drawn into really grand tunneling. Two new
kinds of transport created a need for tunnels.
Railways had to lie on almost flat ground; and so
did England's huge canal system, which had become
its primary commercial trade route. Canals and
railways, like the Roman aqueducts before them,
spawned some heroic tunneling through obstacles.
Typical of these was Marc Brunel's rail tunnel
under the Thames -- the first attempt to work in
the really soft soil under a river. It was begun in
1825 and opened to foot traffic in 1843. During
those 18 years Brunel invented the whole technology
of soft-soil tunneling. He also suffered cave-ins,
deaths, personal injury, and -- in the end -- he
bankrupted his company. The tunnel wasn't opened to
trains until 1865, 40 years after it was begun. But
it's still in use today.
The star-crossed Hoosac tunnel through a mountain
in Western Massachusetts was started as a canal
tunnel in 1851 and completed as a rail tunnel in
1876. It was 26 feet square and 5 miles long; it
consumed 199 lives; and it almost bankrupted
Massachusetts. But the effort also provided all
kinds of new tunneling technology, including the
now common pneumatic drill.
Today those technologies are highly refined, and
some remarkable tunneling goes on without much
fanfare. Who's heard of the 85-mile-long Delaware
aqueduct tunnel that carries water from the
Catskills to New York City? It was finished in
1942.
Tunnels have evoked some amazing engineering; but I
was a child in cold Minnesota, and my favorite
tunnel is the one in John
Greenleaf Whittier 's Snowbound.
To get from the farmhouse to the barn, he says,
We cut the solid whiteness through
And where the drift was deepest, made
A tunnel walled and overlaid
With dazzling crystal: ...
I'm John Lienhard, at the University of
Houston, where we're interested in the way inventive
minds work.
(Theme music)
For more on tunneling, see the proceedings of the
Smithsonian Institution's symposium on its tunneling
exhibition, Down Under: Tunnels Past, Present, and
Future, National Museum of American History,
Saturday, October 23, 1993.
Bobrick, B., Labyrinths of Iron: Subways in
History, Myth, Art, Technology, and War. New
York: Henry Holt And Company, 1981/1986.
Whittier, J. G., Snow-Bound: A Winter Idyl,
New York: The Limited Editions Club, MCMXXX, see
especially, pp. 9-10.
I say more about tunnelling as a metaphor in
Episodes 58, 664, 849
and 855. For more
technical looks at tunnelling, go to the search
function, using the word "tunnel."
This episode has been rewritten as Episode 1388
.
The Engines of Our Ingenuity is
Copyright © 1988-2018 by John H.
Lienhard.
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